Obésité (2019) 14:142-145 DOI 10.3166/obe-2019-0064
REVUE DE PRESSE / PRESS REVIEW
Leptin Mediates the Relationship between Fat Mass and Blood Pressure
Fujita Y, Kouda K, Ohara K, et al. (2019) Medicine [1]
Animal studies have shown that leptin mediates the association between obesity and hypertension. However, only a few studies have assessed this relationship in pop‑
ulation‑based epidemiological studies. This study aimed to determine whether leptin mediates the relationship between body fat and blood pressure in school‑aged children.
A cross‑sectional survey was conducted among school‑aged children in Hamamatsu, Japan. Body fat was measured using dualenergy X‑ray absorptiometry. Height‑normalized index of fat mass (fat mass index) was calculated by divid‑
ing fat mass by height squared. Serum leptin levels were measured by enzyme‑linked immunosorbent assay. Multi‑
ple regression analysis was used to evaluate relationships between body fat, serum leptin levels, and blood pressure.
The mediating effect of leptin on the association between body fat and blood pressure was assessed by causal media‑
tion analysis and regression analysis. Both fat mass index and leptin were significantly and positively associated with blood pressure. Fat mass index was also strongly associated with serum leptin levels. Body fat and blood pressure were no longer associated after adjusting for leptin. These find‑
ings suggest that the association between body fat and blood pressure is mediated by leptin. Of the total effect of fat mass
index on blood pressure, the mediating effect of leptin accounted for 78.6% (P = .03) in boys and 42.2% (P = .11) in girls. Our findings suggest that body fat is associated with blood pressure, and this association is mediated by leptin.
Thus, leptin acts as a mediator that links body adiposity with blood pressure elevation in school‑aged children.
Commentaires : L’obésité infantile est un facteur de risque majeur d’obésité à l’âge adulte et par conséquent le dépistage des complications dès l’enfance est capitale.
Plusieurs études expérimentales sur des animaux ont mis en évidence une élévation de la pression artérielle suite à des injections de leptine. Des modèles d’hyper leptinémie (souris KKA(y)) développent même naturellement une hypertension artérielle (HTA). Les auteurs se penchent ici sur la question de l’HTA sur une cohorte de 400 enfants (âgés de 11,2 ans en moyenne). Dans la mesure où le poids et l’IMC ne reflètent en rien la composition corporelle, l’index de masse grasse mesuré en DEXA est pris en compte dans l’analyse. D’après les auteurs, une association significative est retrouvée entre HTA, index de masse grasse et leptine. Cette association dis‑
paraît après ajustement sur la leptine (car la leptinémie est directement corrélée à la quantité de tissu adipeux). Ainsi la leptine interagirait comme médiateur entre masse grasse et pression artérielle. Des études pour en comprendre la physio pathologie restent nécessaires…
Physical Activity Energy Expenditure and Total Daily Energy Expenditure in Successful Weight Loss Maintainers
Ostendorf D M, Caldwell A E., Creasy S A, et al. (2019) Obesity [2]
Objective: The objective of this study was to compare physical activity energy expenditure (PAEE) and total daily energy expenditure (TDEE) in successful weight loss main‑
tainers (WLM) with normal weight controls (NC) and con‑
trols with overweight/obesity (OC).
Methods: Participants were recruited in three groups:
WLM (n = 25, BMI 24.1 ± 2.3 kg/m2; maintaining ≥ 13.6 kg weight loss for ≥ 1 year), NC (n = 27, BMI 23.0 ± 2.0 kg/m2; similar to current BMI of WLM), and OC (n = 28, BMI V. Florent ∙ B. Gaudrat
V. Florent (*)
Service de nutrition, Centre spécialisé obésité (CSO), centre hospitalier d’Arras, 3 bld Besnier, CS 90006, 62022 Arras cedex, France
Unité Inserm U1172, centre de recherche Jean‑Pierre‑Aubert, Bat. Biserte, 1 place de Verdun 59045 Lille cedex, France e-mail : [email protected]
B. Gaudrat (*)
Service de nutrition, Centre spécialisé obésité (CSO), centre hospitalier d’Arras, 3 bld Besnier, CS 90006, 62022 Arras cedex, France
Laboratoire PSITEC EA4072, université Lille‑III, domaine du Pont‑de‑Bois, BP 60149,
59653 Villeneuve‑d’Ascq cedex, France e-mail : [email protected]
Obésité (2019) 14:142-145 143
34.3 ± 4.8 kg/m2; similar to pre–weight loss BMI of WLM).
TDEE was measured using the doubly labeled water method. Resting energy expenditure (REE) was measured using indirect calorimetry. PAEE was calculated as (TDEE
− [0.1 × TDEE] − REE).
Results: PAEE in WLM (812 ± 268 kcal/d, mean ± SD) was significantly higher compared with that in both NC (621 ± 285 kcal/d, P < 0.01) and OC (637 ± 271 kcal/d, P = 0.02). As a result, TDEE in WLM (2,495 ± 366 kcal/d) was higher compared with that in NC (2,195 ± 521 kcal/d, P = 0.01) but was not significantly different from that in OC (2,573 ± 391 kcal/d).
Conclusions: The high levels of PAEE and TDEE observed in individuals maintaining a substantial weight loss (−26.2 ± 9.8 kg maintained for 9.0 ± 10.2 years) sug‑
gest that this group relies on high levels of energy expended in physical activity to remain in energy balance (and avoid weight regain) at a reduced body weight.
Commentaires : L’étude des changements de dépense énergétique en fonction des variations de poids est passion‑
nante car prédictive de la conduite à tenir afin de garantir un maintien de poids durable. Lors d’une perte de poids importante qu’elle qu’en soit l’origine, il est observé une réduction de la dépense énergétique totale journalière de part une diminution de la dépense énergétique de repos et liée à l’activité physique en raison de la diminution de la masse corporelle. Afin de garantir une stabilité pondérale face à cette diminution de dépense énergétique, la conduite à tenir consiste à maintenir une réduction des apports éner‑
gétiques ou à majorer les dépenses via l’activité physique.
Les auteurs comparent ici chez 106 sujets, la dépense éner‑
gétique en calorimétrie indirecte d’un groupe de patients ayant perdu en moyenne 13,6 kg et maintenu depuis 1 an, à des contrôles normopondéraux et des contrôles en surpoids.
La dépense énergétique liée à l’activité physique observée dans le groupe « maintien de perte de poids » est bien supé‑
rieure aux deux autres groupes et la dépense énergétique totale journalière n’est pas différente du groupe surpoids ! La clef pour garantir un équilibre de la balance énergé‑
tique sur le long terme après amaigrissement semble donc d’avantage liée à la dépense énergétique qu’à la réduction des apports. A confirmer sur des études longitudinales…
The impact of obesity in cognitive and memory dysfunction in obstructive sleep apnea syndrome
Shen YC, Kung SC, Chang ET, et al. (2019) Int J Obes [3]
Objective: Obstructive sleep apnea (OSA), a sleep disor‑
der, results in decreased daytime alertness and neurocognitive dysfunction. Obesity is considered a major risk factor for the
development and progression of OSA and the resulting cog‑
nitive dysfunction. However, the effect of obesity on neuro‑
cognitive dysfunction in OSA has been rarely investigated.
Methods: Eighty‑three patients with moderate to severe OSA syndrome were recruited in our study. After matching for education, age, and body mass index (BMI), 40 patients were enrolled into our study with matched obese (BMI ≥ 30) and non‑obese (BMI < 30) groups. All enrolled patients completed a polysomnographic study, sleepiness question‑
naires, and attention, cognitive, and memory function tests.
Results: Compared to obese OSA patients, non‑obese OSA patients had shorter reaction times in the psychomotor vigilance task but not the Flanker or Stroop cognitive tasks.
Additionally, obese OSA patients had a reduced capacity for working memory relative to non‑obese OSA patients.
Conclusions: Obesity had a significant effect on OSA patients in our study, including delayed reaction times in the psychomotor vigilance task and a decrease in work‑
ing memory.
Commentaires : Le syndrome d’apnées obstructives du sommeil (SAOS), à l’origine d’hypoxémie nocturne et de microréveils, est fréquent chez nos patients obèses dans la mesure où le surpoids est un facteur de risque pour cette pathologie. Il est bien établi que le SAOS conduit à des défi‑
ciences des fonctions cognitives, de mémorisation ou encore de l’attention mais ces déficiences sont indépendantes du niveau de sévérité du SAOS. Par contre, la littérature est très pauvre sur l’étude des fonctions neurocognitives des patients obèses présentant un SAOS. Les auteurs tentent de répondre à cette question en comparant les fonctions neuro‑
cognitives de 83 patients présentant tous un SAOS, obèses ou non. Les résultats sont sans équivoque : les patients obèses présentent un délai de réaction plus lent au test de vigilance ainsi qu’une mémoire de court terme moins per‑
formante comparé aux sujet SAOS non obèses. Cela rejoint le constat d’autres études attestant l’altération des fonc‑
tions neurocognitives chez le sujet obèse, avec des pistes d’étiologie notamment métaboliques.
Mobile Health Applications in Weight Management:
A Systematic Literature Review
Dounavi K, Tsoumani O (2019) Am J Prev Med. [4]
Context: Weight management is an effective strategy for controlling chronic disease and maintaining physical health, and research on this topic has risen dramatically over the past four decades. The present systematic literature review aimed to identify existing evidence on the efficacy of mobile health technology in facilitating weight manage‑
ment behaviors, such as healthy food consumption and physical activity.
144 Obésité (2019) 14:142-145
Evidence acquisition: A systematic search was conducted in Ovid MEDLINE and Ovid PsycINFO databases with the aim to identify studies published in peer‑reviewed journal articles between 2012 and 2017.
Evidence synthesis: A total of 39 studies were analyzed in spring 2018 and are presented here in terms of participant characteristics, effective technology components, additional treatments, impact on health‑related behaviors, and treat‑
ment efficacy. Indicators of study quality and social validity are also provided.
Conclusions: Mobile health apps are widely considered as satisfactory, easy to use, and helpful in the pursuit of weight loss goals by patients. The potential of mobile health apps in facilitating weight loss lies in their ability to increase treat‑
ment adherence through strategies such as self‑monitoring.
These findings indicate that satisfactory treatment adherence and consequent weight loss and maintenance are achieved in the presence of high levels of engagement with a mobile health app. The research quality assessment of RCTs reveals a great need for following international standards both when conducting and reporting research.
Commentaires : Les applications mobiles peuvent‑elles être un atout dans la prise en charge de l’obésité ? Cette revue de la littérature se penche sur ces outils de plus en plus répandus et présentant l’avantage de toucher une large population tout en permettant d’agir au plus proche des patients. Ces applications présentent de hauts degrés d’adhésion et semblent majoritairement efficaces pour faire évoluer le comportement alimentaire et le niveau d’activité physique. Au vu des avantages présentés par ces applica‑
tions en termes d’accessibilité, il est peut‑être temps pour les soignants spécialisés de se saisir de cette opportunité numérique. En effet, si l’adhésion à ces applications est importante, celle‑ci est minorée chez les sujets présentant des troubles du comportement alimentaire et de haut niveau de craving alimentaire. Ainsi l’apport des spécialistes du domaine pourrait permettre de développer des contenus adaptés aux différents profils de patients obèses afin de pro‑
poser des accompagnements spécifiques.
The Short Inventory of Grazing (SIG):
Development and Validation of a New Brief Measure of a Common Eating Behaviour with a Compulsive Dimension
Heriseanu A. I., Hay P. et Touyz S. [2019] Int J Eat Disord. [5]
Background: Grazing, the repetitious and unplanned eat‑
ing of small amounts of food with or without a sense of loss of control (LOC), is an eating pattern of recent inter‑
est which is highly prevalent in eating disorders and obe‑
sity. The current study aimed to (1) assess psychometric
properties of a short inventory of grazing (SIG), consisting of a “grazing in general” item and a “compulsive/LOC graz‑
ing” item and (2) examine associations between compulsive and non‑compulsive grazing and body mass index (BMI), eating disorder psychopathology, distress and health‑related quality of life.
Methods: Participants recruited from a university and the community (n = 227; 75.3% female; age = 25.00 (9.88;
17.58‑57.17) years; BMI = 23.24 (4.91, 14.20‑46.06) kg/m2) completed an online test battery including the SIG. Paramet‑
ric and non‑parametric statistics were computed to assess internal consistency, test‑retest reliability and construct validity, to test associations between the SIG and the other study variables, and to examine between‑group differences.
Results: The SIG demonstrated appropriate psycho‑
metric properties. Results indicated that both grazing in general and low‑frequency LOC grazing are common;
however, LOC grazing of moderate‑severe frequency and/
or associated with marked distress is unusual. Frequency of LOC grazing, but not grazing in general, was significantly associated with higher BMI, psychological distress, com‑
pensatory behaviours and lower mental health‑related qual‑
ity of life. The presence of compulsive grazing was also associated with eating disorder caseness and binge‑type eat‑
ing disorder diagnostic groups.
Conclusions: Results support the positioning of “compul‑
sive” LOC grazing on a continuum of problematic eating.
The SIG is a parsimonious measure of this eating pattern of emergent interest.
Commentaires : Les auteurs présentent ici la validation d’un court questionnaire permettant d’évaluer le grigno‑
tage. Outre sa rapidité et sa facilité d’administration, cet outil présente l’avantage de faire la distinction entre le grignotage avec et sans perte de contrôle. Les résultats de cette étude mettent en évidence que les sujets rapportant du grignotage avec perte de contrôle rapporteraient des IMC supérieurs, des scores de qualité de vie moindres et une détresse plus marquée. Cette étude vient confirmer l’im‑
portance de la perte de contrôle dans l’évaluation de nos patients celle‑ci semblant signifier plus sûrement le retentis‑
sement psychologique que la quantité effectivement ingérée [6,7]. Il serait intéressant de passer cet outil à l’épreuve de la validation en population clinique.
Depression, Emotional Eating and Long‑Term Weight Changes: A Population‑Based Prospective Study Konttinen H, van Strien T, Mannisto S, et al. [2019] Int J Behav Nutr Phys Act [8]
Background: Emotional eating (i.e. eating in response to negative emotions) has been suggested to be one mechanism
Obésité (2019) 14:142-145 145
linking depression and subsequent development of obe‑
sity. However, studies have rarely examined this media‑
tion effect in a prospective setting and its dependence on other factors linked to stress and its management. We used a population‑based prospective cohort of adults and aimed to examine 1) whether emotional eating mediated the associa‑
tions between depression and 7‑year change in body mass index (BMI) and waist circumference (WC), and 2) whether gender, age, night sleep duration or physical activity moder‑
ated these associations.
Methods: Participants were Finnish 25‑ to 74‑year‑olds who attended the DILGOM study at baseline in 2007 and follow‑up in 2014. At baseline (n = 5024), height, weight and WC were measured in a health examination. At fol‑
low‑up (n = 3735), height, weight and WC were based on measured or self‑reported information. Depression (Center for Epidemiological Studies ‑ Depression Scale), emotional eating (Three‑Factor Eating Questionnaire‑R18), physical activity and night sleep duration were self‑reported. Age‑
and gender‑adjusted structural equation models with full information maximum likelihood estimator were used in the analyses.
Results: Depression and emotional eating were positively associated and they both predicted higher 7‑year increase in BMI (R2 = 0.048) and WC (R2 = 0.045). The effects of depression on change in BMI and WC were mediated by emotional eating. Night sleep duration moderated the asso‑
ciations of emotional eating, while age moderated the asso‑
ciations of depression. More specifically, emotional eating predicted higher BMI (P = 0.007 for the interaction) and WC (P = 0.026, respectively) gain in shorter sleepers (7 h or less), but not in longer sleepers (9 h or more). Depres‑
sion predicted higher BMI (P < 0.001 for the interaction) and WC (P = 0.065, respectively) increase in younger par‑
ticipants, but not in older participants.
Conclusions: Our findings offer support for the hypoth‑
esis that emotional eating is one behavioural mechanism between depression and development of obesity and abdom‑
inal obesity. Moreover, adults with a combination of shorter night sleep duration and higher emotional eating may be particularly vulnerable to weight gain. Future research should examine the clinical significance of our observations
by tailoring weight management programs according to these characteristics.
Commentaires : Cette rigoureuse étude longitudinale conduite durant sept années met en évidence que l’alimen‑
tation émotionnelle constituerait un processus expliquant le lien entre dépression et évolution pondérale. De plus, cette étude vient confirmer des résultats antérieurs marquant l’influence du sommeil sur cette médiation entre dépression et cinétique pondérale [9]. En effet, l’influence de l’alimen‑
tation émotionnelle entre dépression et évolution pondérale serait plus marquée chez les « petits dormeurs ». Les résul‑
tats de cette étude poussent à envisager des interventions prenant en charge l’alimentation émotionnelle (et les déficits de régulation dans le domaine) mais ouvre aussi la piste à d’autres accompagnements incluant la variable « sommeil ».
Références
1. Fujita Y, Kouda K, Ohara K, et al. (2019) Leptin mediates the rela‑
tionship between fat mass and blood pressure: The Hamamatsu School‑based health study. Medicine 98: e14934
2. Ostendorf DM, Caldwell AE, Creasy SA, et al. (2019) Physical Activity Energy Expenditure and Total Daily Energy Expenditure in Successful Weight Loss Maintainers. Obesity (Silver Spring) 27: 496‑504
3. Shen YC, Kung SC, Chang ET, et al. (2019) The impact of obesity in cognitive and memory dysfunction in obstructive sleep apnea syndrome. Int J Obes (Lond) 43: 355‑61
4. Dounavi K, Tsoumani O (2019) Mobile Health Applications in Weight Management: A Systematic Literature Review. Am J Prev Med.
5. Heriseanu AI, Hay P, Touyz S (2019) The short inventory of gra‑
zing (SIG): development and validation of a new brief measure of a common eating behaviour with a compulsive dimension. Int J Eat Disord 7: 4
6. Goldschmidt AB, Engel SG, Wonderlich SA, et al. (2012) Momentary affect surrounding loss of control and overeating in obese adults with and without binge eating disorder. Obesity (Silver Spring) 20: 1206‑11
7. Blomquist KK, Roberto CA, Barnes RD, et al. (2014) Develop‑
ment and validation of the eating loss of control scale. Psychol Assess 26: 77‑89
8. Konttinen H, van Strien T, Mannisto S, et al. (2019) Depres‑
sion, emotional eating and long‑term weight changes: a popula‑
tion‑based prospective study. Int J Behav Nutr Phys Act 16: 28 9. van Strien T, Koenders PG (2014) Effects of emotional eating and
short sleep duration on weight gain in female employees. J Occup Environ Med 56: 659‑66
